Building a rotational near field ptychography

Session

Stream 5: Label Free Imaging

Authors

Mr Yiqian Zhang (1)

Affiliations

1. University of Sheffield

Keywords

quantitative phase imaging, Ptychography, Near field Ptychography, Fast data collection,

Abstract text

Near field Ptychography can rebuild complex 2D waves using iterative algorithms and diffraction data collected from optical microscopy systems. It demonstrates excellent phase sensitivity with a high field of view (FOV) and undemanding alignment procedures. However, Ptychography usually involves sample movement, so the quality of reconstruction and data collection time are considerably worse when the object is fluid. In this poster, I will introduce a modified method for data collection which is based on near field Ptychography. Instead of scanning the object step by step, a rotating aperture is used to introduce diversity into the ptychography process hence, the sample stays unchanged during the experiment. This idea can deliver high accuracy phase images with a small number of measured diffraction patterns, it is quick, and it can be added on very simply to an existing microscope platform.

References

[1]A. Maiden and J. Rodenburg, "An improved ptychographical phase retrieval algorithm for diffractive imaging", 2009.

[2]S. McDermott and A. Maiden, "Near-field ptychographic microscope for quantitative phase imaging", 2018.

[3]Y. Geng et al., "Enhanced multi-rotation computational coherent imaging based on pre-illumination and simulated annealing compensation", 2019.